Semiconductor integrated circuits are continually becoming smaller due to demands for device compactness and increased circuit complexity. Electrical circuitry have shrunken and are typically positioned in very close proximity to increase circuit density. As a result, closely positioned circuitry may influence the operation of one another. For example, output signal drivers often drive signals onto parallel signal lines that are in close proximity to one another, such as onto a data channel. Typical data channels have a plurality of closely spaced signal lines on which data signals are transmitted.
Due to the proximity of the signal lines, issues of crosstalk and pattern dependent impedance mismatch may cause signal transitions on one signal line to be affected by signal transitions on one or more adjacent signal lines. Signals on adjacent signal lines that are transitioning to opposite logic levels (e.g., representing different data states) may inhibit one or more of the signals from transitioning as quickly as desired due to crosstalk. As a result, the signals may take longer to reach a desired logic level thus compromising performance. Even in instances where a signal transitioning on a signal line that is adjacent to signal lines on which one or more of the signals is not transitioning or adjacent to signal lines on which one or more of the signals is not transitioning to another logic level may be affected by crosstalk.
Transitioning signals on adjacent signal lines may also result in pattern dependent impedance mismatch, as previously mentioned. Pattern dependent impedance mismatch may cause adjacent signal lines having transitioning signals to effectively change impedance from a nominal (e.g., expected) impedance. This may result in signal reflections on the signal line and signal interference, again compromising performance.